BOSTON — Deep-blue Massachusetts may seem an unlikely battleground in the fight over transgender rights. But supporters and opponents alike say a November ballot question on whether to strike down the state’s recently enacted law protecting transgender individuals in public spaces could be the next cruciblein the national debate.

“Both sides recognize this vote has national implications. If this movement can be stopped in Massachusetts, it can be stopped anywhere in the country,” said Andrew Beckwith, president of the Massachusetts Family Institute, which opposes the commonwealth’s 2016 transgender protection law.

Despite its liberal reputation, Massachusetts has plenty of socially conservative pockets (and routinely elects moderate GOP governors, like current Gov. Charlie Baker). But proponents of the Massachusetts law are worried that support for it is weak enough that a concerted effortby opponents of transgender rights could create a public firestorm like the one that gripped North Carolina in 2016, and lead voters to overturn the law.

The repeal question “made it to the ballot — clearly it needs to be taken seriously,” said Boston Chamber CEO Jim Rooney, whose organization backs the law and opposes the ballot question. “With the national reputation of the state, while there is a demonstrated history of a progressive bent on social issues, it’s not to say it’s a homogeneous state where everyone thinks the same.”

The ballot battle will come amid a competitive 2018 election cycle in the Boston media market, which will include competitive congressional races in eastern Massachusetts and southern New Hampshire, and governors races in both states. The November ballot in Massachusetts will also have other high-profile questions for voters, including an option to drop the state’s sales tax, and a potential tax increase on those earning more than $1 million annually.

The debate alreadyhas echoes of the contentious 2016 fight in Raleigh: “Keep Massachusetts Safe” is the official group pushing the ballot question here, just as the proponents of the ban against transgender public accommodation protections were a group known as “Keep North Carolina Safe.”

North Carolina’s law required transgender individuals to use bathrooms in line with the gender listed on their birth certificate. The Associated Press calculated that the state could suffer nearly $4 billion in lost business over the course of 12 years because of the law, and portions of it were repealed in 2017 after the NCAA and other business and sports groups took steps to sanction or boycott the state.

Still, a 2015 campaign in Houston that successfully blocked a city ordinance to protect against discrimination based on sexual orientation and gender identity has proponents of Massachusetts’ law worried.

Democratic-leaning Houston is far more liberal than the rest of beet-red Texas — its voters elected a lesbian mayor for three terms and have voted for the Democratic presidential candidate since 2008. But the 2015 ballot question was voted down 61 percent to 39 percent, a margin largely attributable to opponents’ straightforward message: “No men in women’s bathrooms.”

“We are confident in Massachusetts voters, but we take nothing for granted,” says Kasey Suffredini, co-chair of Freedom for All Massachusetts, which supported the law’s passage in 2016 and is now at work defending it this November. “The high-profile defeat in a similar fight in Houston in 2015 showed us that our opponents will lie to voters to make them uncomfortable with transgender people, and that tactic can win.”

The law’s supporters are working to haul in cash for ad buys. Freedom for All Massachusetts is gearing up to raise at least $5 million, says Suffredini. It is taking a page from the 2016 campaigns, when a ballot question on expanding charter schools in Massachusetts attracted national attention — and national donors.

In 2017, Freedom for All Massachusetts raised $386,000, with donors including Harvard Pilgrim Health Care, the ACLU, and the Service Employees International Union’s PAC. Keep MassachusettsSafe brought in just $13,400 during that same period.

“What you’ll typically see is the ‘yes’ campaign will have leads in public polls. When people start to focus on both sides’ argument, [the] race starts to tighten up,” says George Cronin, managing director of Rasky Partners‘ public affairs practice and a veteran of Massachusetts ballot question campaigns. “If the ‘no’ side can come up with an effective, powerful, coherent message, they can persuade based on that message. It will depend on what kind of a message the ‘no’ campaign settles on.”

The waters are also muddied by the fact that high-profile issues that directly hit voters’ pocketbooks will also be on the ballot, and competing for airtime.

“It really is a public education fight. [We have to] encapsulate the issue because people are busy,” said Beckwith, of the Massachusetts Family Institute. He acknowledges that in the campaign to strike down the law, “we assume we’ll be outspent. We’ll do the best we can to raise as much money as we can.”

Keep Massachusetts Safe has so far seen the vast majority of its donations limited to in-state contributions. Of other major national conservative groups who have been involved in campaigns like the one in North Carolina, only the conservative Family Policy Alliance says it is “still evaluating whether we will give a monetary grant toward this referendum,” said spokesperson Autumn Stroup. Family Policy Alliance, which considers the Massachusetts Family Institute a state-based member of its alliance, has provided resources and behind-the-scenes support related to the law, she added.

Beckwith said he anticipated that other national conservative groups, like the Alliance Defending Freedom and the Family Research Council, both of whom were engaged in the North Carolina campaign, would get involved. Spokespersons for both groups told POLITICO they have no plans to get involved at this time.

“I’m sure the folks that watch this, if you’re on the yes side, you’ll be nervously watching whether late money will get involved, if they’re able to move things towards the end,” Cronin said. “That’s always a concern.”

Like in North Carolina, sports teams have played a key role in Massachusetts: The Red Sox were the first professional sports team in the state to back the accommodations proposal itself in 2015, before it became law, and will defend it through the ballot question campaign.

“The ideas that they’re championing are in keeping with the overarching goals of our organization, to make Fenway Park as welcoming to as many groups as possible, regardless of race, sexual orientation, gender,” said Zineb Curran, vice president of corporate communications for the Red Sox.

Economic impact plays a role in the business community’s calculus too. “What we need as a business is access to talent. It doesn’t matter what state you’re in, every company is looking for more talent,” said Eastern Bank Vice President Nancy Huntington Stager. She’s also Freedom for All Massachusetts’ business campaign co-chair. “It’s good for business to have certainty. It’s not good to have people boycotting or not wanting to visit your state.”

As Suffredini put it: “There’s no question in this climate that with a vote to repeal discrimination protections, there will be consequences for Massachusetts if it goes in that direction.”